Introducing Materials Science: Experimenting with Magnetic Nanomaterials in the Undergraduate Chemistry Laboratory.

Materials science research has expanded significantly in recent years; a multidisciplinary field, home to an ever-growing number of chemists. However, our general chemistry degree courses have not changed to reflect the rise in interest in this topic. In this paper, we propose a laboratory experiment for the undergraduate chemistry practical course, which may serve as a hands-on introduction to this field. The experiment involves the synthesis and characterization of magnetic materials via commonly employed techniques in materials science. Students begin by producing three metal ferrite spinels using a sol-gel combustion synthesis. They must then characterize the differing magnetic properties across their three samples using a magnetic susceptibility balance. In the second part of the experiment, students must create a ferrofluid via coprecipitation, from which they may observe the phenomenon of "spiking" in response to an external magnet. Additional data such as X-ray diffraction (XRD) patterns and transmission electron microscopy (TEM) images corresponding to these materials are also provided, and students are tasked with the interpretation of these data in their writeup report. Upon completion, students should gain a new-found understanding of materials science and its fundamental overlap with chemistry.

Supplementation with Sunflower/Fish Oil-Containing Concentrates in a Grass-Based Beef Production System: Influence on Fatty Acid Composition, Gene Expression, Lipid and Colour Stability and Sensory Characteristics of Longissimus Muscle.

Beef contains an array of conjugated linoleic acid (CLA) isomers for which positive effects have been reported in animal models of human disease. The objectives were to develop a CLA-enriched beef production system and to assess its quality. Sixty Spring-born heifers were housed in Autumn and offered unwilted grass silage and a barley/soyabean concentrate or wilted grass silage and a concentrate containing sunflower oil and fish oil. In May, both groups were offered either pasture for 22 weeks, restricted pasture and sunflower oil and fish oil for 22 weeks, or pasture for 11 weeks and restricted pasture and sunflower oil and fish oil for the final 11 weeks. The predominant CLA isomer in beef was cis9, trans11 representing on average, 80% total CLA. The modified winter diet followed by supplementation for 22 weeks resulted in beef that had a CLA concentration that was higher, at a comparable intramuscular fatty acid concentration, than previously reported. The lipid and colour stability (over 10 days in modified atmosphere packaging) and sensory characteristics were generally not negatively affected. There were minor effects on the expression of candidate genes involved in lipid metabolism. Consumption of this beef would make a substantial contribution to the quantity of CLA suggested to have a positive effect on consumer health.

Partially oxidised boron nitride as a 2D nanomaterial for nanofiltration applications.

Boron nitride (BN) based 2D nanomaterials are an emerging class of materials for the development of new membranes for nanofiltration applications. Here, we report the preparation, characterisation and testing of highly promising nanofiltration membranes produced from partially oxidised BN (BNOx) 2D nanosheets. In our work, the partial oxidation of BN was successfully achieved by heating the bulk h-BN powder in air at 1000 °C, resulting in BNOx product. The characterisation of the sample showed the presence of B-OH groups corresponding to the partial oxidisation of the BN. The BNOx material was then exfoliated in water and used to produce membranes, using vacuum filtration. These membranes were characterised using electron microscopy, BET and mercury porosimetry techniques. The membranes have also been tested in water purification and removal of several typical water-soluble dyes, demonstrating outstanding retention values close to 100%. We believe that this research opens up new opportunities for further production, as well as chemical functionalisation and modification of membranes for nanofiltration and separation technologies.

Collective Effects in Ionic Liquid [emim][Tf2N] and Ionic Paramagnetic Nitrate Solutions without Long-Range Structuring.

Mesoscopic shear elasticity has been revealed in ordinary liquids both experimentally by reinforcing the liquid/surface interfacial energy and theoretically by nonextensive models. The elastic effects are here examined in the frame of small molecules with strong electrostatic interactions such as room temperature ionic liquids [emim][Tf2N] and nitrate solutions exhibiting paramagnetic properties. We first show that these charged fluids also exhibit a nonzero low-frequency shear elasticity at the submillimeter scale, highlighting their resistance to shear stress. A neutron scattering study completes the dynamic mechanical analysis of the paramagnetic nitrate solution, evidencing that the magnetic properties do not induce the formation of a structure in the solution. We conclude that the elastic correlations contained in liquids usually considered as viscous away from any phase transition contribute in an effective way to collective effects under external stress whether mechanical or magnetic fields.

High-Performance Boron Nitride-Based Membranes for Water Purification.

In recent years, nanotechnology-based approaches have resulted in the development of new alternative sustainable technologies for water purification. Two-dimensional (2D) nanomaterials are an emerging class of materials for nanofiltration membranes. In this work, we report the production, characterisation and testing of a promising nanofiltration membrane made from water-exfoliated boron nitride (BN) 2D nanosheets. The membranes have been tested for water purification and removal of typical water-soluble dyes such as methyl orange, methylene blue and Evans blue, with the water-exfoliated BN membranes achieving retention values close to 100%. In addition, we compared the performance of membranes made from water-exfoliated BN with those produced from BN using sonication-assisted liquid exfoliation in selected organic solvents such as 2-propanol and N-methyl-2-pyrrolidone. It was found that membranes from the water-exfoliated BN showed superior performance. We believe this research opens up a unique opportunity for the development of new high-performance environmentally friendly membranes for nanofiltration and new sustainable separation technologies.

Fluid Drag Reduction by Magnetic Confinement.

The frictional forces of a viscous liquid flow are a major energy loss issue and severely limit microfluidics practical use. Reducing this drag by more than a few tens of percent remain elusive. Here, we show how cylindrical liquid-in-liquid flow leads to drag reduction of 60-99% for sub-mm and mm-sized channels, regardless of whether the viscosity of the transported liquid is larger or smaller than that of the confining one. In contrast to lubrication or sheath flow, we do not require a continuous flow of the confining lubricant, here made of a ferrofluid held in place by magnetic forces. In a laminar flow model with appropriate boundary conditions, we introduce a modified Reynolds number with a scaling that depends on geometrical factors and viscosity ratio of the two liquids. It explains our whole range of data and reveals the key design parameters for optimizing the drag reduction values. Our approach promises a new route for microfluidics designs with pressure gradient reduced by orders of magnitude.

Effects of different levels of dietary black cumin (Nigella sativa L.) and fenugreek (Trigonella foenum-graecum L.) and their combination on productive traits, selected blood constituents, microbiota and immunity of broilers.

The effects of inclusion of powdered seeds of black cumin (B) (Nigella sativa L.) and fenugreek (F) (Trigonella foenum-graecum L.) on productive traits, selected blood constituents, microbiota and immunity of broilers were studied. A total of 648 day-old chicks were randomly assigned to nine treatments, with four pen replicates, each with 18 birds, including three levels of B seed powder (BSP; 0, 5 or 10 g/kg) and three levels of F seed powder (FSP; 0, 5 or 10 g/kg) in a 3 × 3 factorial arrangement. Neither powder affected feed intake. The FSP increased (p = 0.048) feed conversion ratio (FCR), but decreased daily BW gain (p = 0.02) between days 0 and 21, while BSP increased daily gain between days 22 and 42 and overall (both p = 0.005). Abdominal fat was decreased (p = 0.003) by BSP. Blood constituents were unaffected by either powder, but ileal Escherichia coli were decreased (p = 0.039) at day 42. The BSP increased a range of immunological titers, where BSP affected positively the measured variables. The interactions between BSP and FSP, specifically on broiler carcass cuts, suggested that where BSP is included at 10 g/kg, the inclusion of FSP at the same level may provide no additional benefit. Thus, while either powder could be included separately, the co-inclusion of both at 10 g/kg is not recommended.

Effect of Essential Oil of Thyme (Thymus vulgaris L.) or Increasing Levels of a Commercial Prebiotic (TechnoMOS®) on Growth Performance and Carcass Characteristics of Male Broilers.

To investigate the effect of thyme (Thymus vulgaris L.) essential oil (TEO) or increasing inclusion of a prebiotic (TechnoMOS®) on growth performance and carcass characteristics of Ross 308 broilers, 400 one-day-old male broilers (43.5 g, as mean of body weight) were placed in 20 pens (2.0 × 1.0 m, with a floor area of 0.10 m2 per bird) in groups of 20, and each pen cage was assigned to a specific dietary treatment (four replicates per each one). The dietary treatments included basic diet (no additive; CTR), basic diet including 0.025%, 0.075%, or 0.125% of TechnoMOS® (MOS025, MOS075, and MOS125, respectively), or basic diet including 0.075% thyme extract (TEO075). All dietary treatments were offered from the beginning of the study until the end of the trial. There were no effects of MOS or TEO on carcass characteristics. No significant effects of treatment on weight gain were obtained on a week-by-week basis; however, CTR birds gained less weight during the grower phase and overall compared with MOS birds. The same contrast for feed intake revealed that CTR birds had greater feed intake than MOS birds during both the grower phase and overall (492.18 g and 486.35 g, respectively). In conclusion, treated groups showed an improved feed conversion ratio.

Magnetic Control over the Fractal Dimension of Supramolecular Rod Networks.

Controlling supramolecular polymerization is of fundamental importance to create advanced materials and devices. Here we show that the thermodynamic equilibrium of Gd3+-bearing supramolecular rod networks is shifted reversibly at room temperature in a static magnetic field of up to 2 T. Our approach opens opportunities to control the structure formation of other supramolecular or coordination polymers that contain paramagnetic ions.

Helium Ion Microscopy for Reduced Spin Orbit Torque Switching Currents.

Spin orbit torque driven switching is a favorable way to manipulate nanoscale magnetic objects for both memory and wireless communication devices. The critical current required to switch from one magnetic state to another depends on the geometry and the intrinsic properties of the materials used, which are difficult to control locally. Here, we demonstrate how focused helium ion beam irradiation can modulate the local magnetic anisotropy of a Co thin film at the microscopic scale. Real-time in situ characterization using the anomalous Hall effect showed up to an order of magnitude reduction of the magnetic anisotropy under irradiation, with multilevel switching demonstrated. The result is that spin-switching current densities, down to 800 kA cm-2, can be achieved on predetermined areas of the film, without the need for lithography. The ability to vary critical currents spatially has implications not only for storage elements but also neuromorphic and probabilistic computing.

Liquid flow and control without solid walls.

When miniaturizing fluidic circuitry, the solid walls of the fluid channels become increasingly important1 because they limit the flow rates achievable for a given pressure drop, and they are prone to fouling2. Approaches for reducing the wall interactions include hydrophobic coatings3, liquid-infused porous surfaces4-6, nanoparticle surfactant jamming7, changes to surface electronic structure8, electrowetting9,10, surface tension pinning11,12 and use of atomically flat channels13. A better solution may be to avoid the solid walls altogether. Droplet microfluidics and sheath flow achieve this but require continuous flow of the central liquid and the surrounding liquid1,14. Here we demonstrate an approach in which aqueous liquid channels are surrounded by an immiscible magnetic liquid, both of which are stabilized by a quadrupolar magnetic field. This creates self-healing, non-clogging, anti-fouling and near-frictionless liquid-in-liquid fluidic channels. Manipulation of the field provides flow control, such as valving, splitting, merging and pumping. The latter is achieved by moving permanent magnets that have no physical contact with the liquid channel. We show that this magnetostaltic pumping method can be used to transport whole human blood with very little damage due to shear forces. Haemolysis (rupture of blood cells) is reduced by an order of magnitude compared with traditional peristaltic pumping, in which blood is mechanically squeezed through a plastic tube. Our liquid-in-liquid approach provides new ways to transport delicate liquids, particularly when scaling channels down to the micrometre scale, with no need for high pressures, and could also be used for microfluidic circuitry.

Dehydration of the Uranyl Peroxide Studtite, [UO2(η2-O2)(H2O)2]·2H2O, Affords a Drastic Change in the Electronic Structure: A Combined X-ray Spectroscopic and Theoretical Analysis.

The minerals studtite, [UO2(η2-O2)(H2O)2]·2H2O, and metastudtite, [UO2(η2-O2)(H2O)2], are uranyl peroxide minerals that are major oxidative alteration phases of UO2 under conditions of geological storage. The dehydration of studtite has been studied using X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy. XPS of the U 4f region shows small but significant differences between studtite and metastudtite, with the 4f binding energy of studtite being the highest reported for a uranyl mineral studied by this technique. Further information about the changes in the electronic structure was elucidated using U M4-edge high-energy resolution X-ray absorption near-edge structure (HR-XANES) spectroscopy, which directly probes f orbital states. The transition from the 3d to 5fσ* orbital is sensitive to variations in the U═Oaxial bond length and to changes in the bond covalency. We report evidence that the covalence in the uranyl fragment decreases upon dehydration. Photoluminescence spectroscopy at near-liquid helium temperatures reveals significant spectral differences between the two materials, correlating with the X-ray spectroscopy results. A theoretical investigation has been conducted on the structures of both studtite and metastudtite and benchmarked to the HR-XANES spectra. These illustrate the sensitivity of the 3d to 5f σ* transition toward U═Oaxial bond variation. Small structural changes upon dehydration have been shown to have an important electronic effect on the uranyl fragment.

Transgender Sterilisation Requirements in Europe.

The possibility of individuals procreating post-transition has long stalked debates on transgender rights. In 1972, Sweden became the first European jurisdiction to formally acknowledge preferred gender. Under the original Swedish law, applicants for gender recognition were explicitly required to prove an incapacity to reproduce-either through natural infertility or through a positive act of sterilisation. Across the Council of Europe, 20 countries continue to enforce a sterilisation requirement. When considering reforms to their current gender recognition rules as recently as 2015, the Polish executive and the Finnish legislature both rejected proposals to remove mandatory infertility provisions. This article critiques the rationales for transgender sterilisation in Europe. It places transgender reproduction, and non-traditional procreation, in the wider context of European equality and family law. Adopting a highly inter-disciplinary framework, the article explores legal, social, medical, and moral arguments in favour of sterilisation, and exposes the weak intellectual and evidential basis for the current national laws. The article ultimately proposes a new departure for Europe's attitude towards transgender parenting, and argues that sterilisation should not be a pre-condition for legal recognition.

Continuous hydrothermal synthesis of Ca2Al-NO3 layered double hydroxides: The impact of reactor temperature, pressure and NaOH concentration on crystal characteristics.

Continuous hydrothermal synthesis (CHS) of nanoparticles is most commonly associated with the production of metal oxides and ceramics. However, recent work has demonstrated that layered double hydroxides (LDH) can also be synthesised via this method. This research investigates how altering temperature, pressure and precursor base concentration affects growth and nucleation rates which impact on LDH characteristics. Experiments examined the separate effects of increased temperature, pressure and NaOH concentration on crystal domain length (CDL) and surface area. Adjustments to temperature and pressure in the reactor system resulted in variations in CDL. High temperature (200°C) with increasing pressure resulted in an increase in CDL between 50bar and 100bar, then a decrease up to 200bar. Crystal domain length of samples synthesised at 75°C and 150°C showed increases between 50bar and 150bar but a decrease at higher pressure. Variation in CDL showed little impact on specific surface area (4-7m2g-1). Increasing NaOH decreased CDL. High precursor NaOH causes rapid nucleation to occur to the detriment of crystal growth. Samples with 1M and 0.5M NaOH exhibit Ca(OH)2 impurities as the increased NaOH causes precipitation of Ca2+.

Supramolecular pathway selection of perylenediimides mediated by chemical fuels.

We demonstrate supramolecular pathway selection of a perylenediimide derivative in aqueous solution using chemically fueled redox reactions to control assembly/disassembly cycles. The number and frequency of cycles affect the nucleation and growth process, providing control over the size and internal order of the resulting self-assembled structures.

Continuous-flow hydrothermal synthesis for the production of inorganic nanomaterials.

As nanotechnology becomes increasingly important and ubiquitous, new and scalable synthetic approaches are needed to meet the growing demand for industrially viable routes to nanomaterial production. Continuous-flow hydrothermal synthesis or supercritical water hydrothermal synthesis (scWHS) is emerging as a versatile solution to this problem. The process was initially developed to take advantage of the tunable chemical and physical properties of superheated water to produce metal oxide nanoparticles by rapid nucleation and precipitation. The development of new mixing regimes and reactor designs has been facilitated by the modelling of reactor systems. These new reactor designs further exploit the properties of supercritical water to promote faster and more uniform mixing of reagent streams. The synthetic approach has been expanded beyond the metal oxide systems for which it was conceived, and now encompasses metal sulfides, metal phosphates, metal nanoparticles and metal-organic frameworks. In many of these cases, some degree of size and shape control can be achieved through careful consideration of both chemistry and reactor design. This review briefly considers the development of scWHS reactor technology, before highlighting some of our recent work in expanding the scope of this synthetic method to include a wide range of materials.

YY v TURKEY: INFERTILITY AS A PRE-CONDITION FOR GENDER CONFIRMATION SURGERY.

In YY v Turkey, the Second Chamber of the European Court of Human Rights (ECtHR) held that Turkey's refusal, over a period of many years, to authorise gender confirmation surgery because the applicant remained capable of procreating was a violation of the right to private life under Art. 8 of the European Convention on Human Rights. The Second Chamber's judgment acknowledges, and gives practical effect to, the 'physical and moral security' of transgender persons. YY has the potential to revolutionise gender confirming health care in Europe and will hopefully ensure that, where individuals do seek to medically transition, they need only access to treatments that are both necessary and desired. The ECtHR's decision may also impact upon the legal recognition of transgender identities. While not the direct focus of the Second Chamber's assessment, legal gender recognition is a constant theme throughout the judgment, and many of the Court's arguments are equally applicable to legal schemes for acknowledging preferred gender.

The sequential continuous-flow hydrothermal synthesis of molybdenum disulphide.

Molybdenum disulphide (MoS2) has been widely used as a catalyst and high temperature lubricant. It has been heavily researched recently as a graphene analogue and member of the so-called inorganic fullerenes. Here we report the first continuous flow hydrothermal synthesis of MoS2. With fast reaction times and flexibility the continuous flow hydrothermal system allowed MoS2 to be produced in a stepwise fashion, offering an insight into the mechanism involved. It has been found that the synthesis of MoS2 proceeded via the sulphidation of molybdate anions to thiomolybdate species, which are transformed to amorphous MoS3 by acidification in flow, before further hydrothermal treatment decomposes this amorphous precursor to tangled MoS2 nanosheets.

The rapid size- and shape-controlled continuous hydrothermal synthesis of metal sulphide nanomaterials.

Continuous flow hydrothermal synthesis offers a cheap, green and highly scalable route for the preparation of inorganic nanomaterials which has predominantly been applied to metal oxide based materials. In this work we report the first continuous flow hydrothermal synthesis of metal sulphide nanomaterials. A wide range of binary metal sulphides, ZnS, CdS, PbS, CuS, Fe(1-x)S and Bi2S3, have been synthesised. By varying the reaction conditions two different mechanisms may be invoked; a growth dominated route which permits the formation of nanostructured sulphide materials, and a nucleation driven process which produces nanoparticles with temperature dependent size control. This offers a new and industrially viable route to a wide range of metal sulphide nanoparticles with facile size and shape control.

The synthesis of organo-soluble anatase nanocrystals from amorphous titania.

Highly soluble anatase nanocrystals of 4 nm diameter have been prepared by the reaction of amorphous titania with trifluoroacetic acid. The solubility of the nanocrystals is a result of surface bound carboxylate groups, and enables the organic-inorganic hybrid material to be processed from solution to yield high quality coatings and thin-films.